CMake/Modules/CheckFunctionExists.cmake

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# - Check if a C function can be linked
# CHECK_FUNCTION_EXISTS(<function> <variable>)
#
# Check that the <function> is provided by libraries on the system and
# store the result in a <variable>. This does not verify that any
# system header file declares the function, only that it can be found
# at link time (considure using CheckSymbolExists).
#
# The following variables may be set before calling this macro to
# modify the way the check is run:
#
# CMAKE_REQUIRED_FLAGS = string of compile command line flags
# CMAKE_REQUIRED_DEFINITIONS = list of macros to define (-DFOO=bar)
# CMAKE_REQUIRED_INCLUDES = list of include directories
# CMAKE_REQUIRED_LIBRARIES = list of libraries to link
#=============================================================================
# Copyright 2002-2011 Kitware, Inc.
#
# Distributed under the OSI-approved BSD License (the "License");
# see accompanying file Copyright.txt for details.
#
# This software is distributed WITHOUT ANY WARRANTY; without even the
# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the License for more information.
#=============================================================================
# (To distribute this file outside of CMake, substitute the full
# License text for the above reference.)
include("${CMAKE_CURRENT_LIST_DIR}/CMakeExpandImportedTargets.cmake")
macro(CHECK_FUNCTION_EXISTS FUNCTION VARIABLE)
if("${VARIABLE}" MATCHES "^${VARIABLE}$")
set(MACRO_CHECK_FUNCTION_DEFINITIONS
"-DCHECK_FUNCTION_EXISTS=${FUNCTION} ${CMAKE_REQUIRED_FLAGS}")
message(STATUS "Looking for ${FUNCTION}")
if(CMAKE_REQUIRED_LIBRARIES)
# this one translates potentially used imported library targets to their files on disk
CMAKE_EXPAND_IMPORTED_TARGETS(_ADJUSTED_CMAKE_REQUIRED_LIBRARIES LIBRARIES ${CMAKE_REQUIRED_LIBRARIES} CONFIGURATION "${CMAKE_TRY_COMPILE_CONFIGURATION}")
set(CHECK_FUNCTION_EXISTS_ADD_LIBRARIES
"-DLINK_LIBRARIES:STRING=${_ADJUSTED_CMAKE_REQUIRED_LIBRARIES}")
else()
set(CHECK_FUNCTION_EXISTS_ADD_LIBRARIES)
endif()
if(CMAKE_REQUIRED_INCLUDES)
set(CHECK_FUNCTION_EXISTS_ADD_INCLUDES
"-DINCLUDE_DIRECTORIES:STRING=${CMAKE_REQUIRED_INCLUDES}")
else()
set(CHECK_FUNCTION_EXISTS_ADD_INCLUDES)
endif()
try_compile(${VARIABLE}
${CMAKE_BINARY_DIR}
${CMAKE_ROOT}/Modules/CheckFunctionExists.c
COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS}
CMAKE_FLAGS -DCOMPILE_DEFINITIONS:STRING=${MACRO_CHECK_FUNCTION_DEFINITIONS}
"${CHECK_FUNCTION_EXISTS_ADD_LIBRARIES}"
"${CHECK_FUNCTION_EXISTS_ADD_INCLUDES}"
OUTPUT_VARIABLE OUTPUT)
if(${VARIABLE})
set(${VARIABLE} 1 CACHE INTERNAL "Have function ${FUNCTION}")
message(STATUS "Looking for ${FUNCTION} - found")
file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
"Determining if the function ${FUNCTION} exists passed with the following output:\n"
"${OUTPUT}\n\n")
else()
message(STATUS "Looking for ${FUNCTION} - not found")
set(${VARIABLE} "" CACHE INTERNAL "Have function ${FUNCTION}")
file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
"Determining if the function ${FUNCTION} exists failed with the following output:\n"
2003-07-17 22:55:45 +04:00
"${OUTPUT}\n\n")
endif()
endif()
endmacro()